IIS Server and Spring.NET object instantiation failed

Your web.config lacks parts of the required configuration, from the docs:

Configuration for IIS 7.0 on Windows Server 2008, Win7 and Windows  Vista

There is some configuration that is specific to using IIS7, the  appropriate code snippit to place in web.config shown below.

<system.webServer>
  <validation validateIntegratedModeConfiguration="false"/>
  <modules>
    <add name="Spring" type="Spring.Context.Support.WebSupportModule, Spring.Web"/>
  </modules>
  <handlers>
    <add name="SpringPageHandler" verb="*" path="*.aspx" type="Spring.Web.Support.PageHandlerFactory, Spring.Web"/>
    <add name="SpringWebServiceHandler" verb="*" path="*.asmx" type="Spring.Web.Services.WebServiceHandlerFactory, Spring.Web" />
    <add name="SpringContextMonitor" verb="*" path="ContextMonitor.ashx" type="Spring.Web.Support.ContextMonitor, Spring.Web"/>
  </handlers>
</system.webServer>